Change .open to use feature detection instead

Signed-off-by: William So <[email protected]>

.changeset/yellow-islands-laugh.md

@@ -0,0 +1,5 @@
+---
+"@polyipseity/obsidian-plugin-library": minor
+---
+
+Change `$FileSystem.open` to use feature detection instead.

sources/@types/obsidian.ts

@@ -33,8 +33,6 @@ import type {
 	SettingTab,
 	UnknownSettingTab,
 } from "obsidian"
-import type { Deopaque } from "../types.js"
-import type { Platform } from "../platform.js"
 import type { Private } from "../private.js"
 
 declare const PRIVATE_KEY: unique symbol
@@ -67,9 +65,9 @@ interface $DataAdapter {
 }
 
 interface $FileSystem {
-	readonly open: <T extends Platform.Current>(
-		path: Deopaque<T> extends Platform.Mobile ? string : never,
-	) => Deopaque<T> extends Platform.Mobile ? PromiseLike<void> : never
+	readonly open?: <Length extends number>(
+		path: Length extends 1 ? string : never,
+	) => Length extends 1 ? PromiseLike<void> : never
 }
 
 interface $Plugins {

sources/obsidian.ts

@@ -30,7 +30,6 @@ import {
 	cloneAsWritable,
 	createChildElement,
 	deepFreeze,
-	inSet,
 	instanceOf,
 	multireplace,
 	onVisible,
@@ -40,7 +39,6 @@ import { cloneDeep, constant, noop } from "lodash-es"
 import { revealPrivate, revealPrivateAsync } from "./private.js"
 import type { AsyncOrSync } from "ts-essentials"
 import { InternalDOMClasses } from "./internals/magic.js"
-import { Platform } from "./platform.js"
 import type { PluginContext } from "./plugin.js"
 import { around } from "monkey-around"
 import { saveAs } from "file-saver"
@@ -486,20 +484,21 @@ export async function saveFileAs(
 	adapter: DataAdapter,
 	data: File,
 ): Promise<void> {
-	const { CURRENT, MOBILE } = Platform
-	if (inSet(MOBILE, CURRENT)) {
-		await revealPrivateAsync(context, [adapter], async ({ fs }) => {
-			await fs.open<typeof CURRENT>(
+	if (await revealPrivateAsync(context, [adapter], async ({ fs }) => {
+		if ("open" in fs && fs.open.length === 1) {
+			const { length } = fs.open
+			await fs.open<typeof length>(
 				(await Filesystem.writeFile({
 					data: await data.text(),
 					directory: Directory.Cache,
 					encoding: Encoding.UTF8,
 					path: data.name,
 				})).uri,
 			)
-		}, noop)
-		return
-	}
+			return true
+		}
+		return false
+	}, constant(false))) { return }
 	saveAs(data)
 }